Rear crossover pipe????

[Jbuhr]

I posted this question on another forum and haven't gotten any responses.

Hi. I'm building a turbo 340 Duster. I've been looking at the pics of builds on the forum. My goal is to keep the alternator and power steering in the stock locations. I want to run the crossover pipe under the transmission with the left feeding the right. I want to weld the turbo flange to the right side manifold, then plumb the intercooler tubing forward. My theory is that is should work just fine. Its not how most people on this site are doing it. Most are running the crossover in front of the engine.

Who has done this? What are the cons?

Jessie Buhr

 

[67Dart273]

There was a system that did just that, became part of Accel? I believe, was orginally Roto-Master "All the junk" that the carb sets on you would not have to use. This was supposed to act like a low RPM bypass deal so that the carb fed the engine "straight through" at no boost


http://www.forabodiesonly.com/mopar/showthread.php?t=222990

From this thread:

http://www.forabodiesonly.com/mopar/showthread.php?t=187891

is this photo of the special passenger side manifold they used

From this thread is the "Chivvy" version:

http://www.theturboforums.com/threads/352986-can-i-run-my-turbo-drain-in-to-my-valve-cover

In the photo below, the crossover comes off the flange pointing to the rear inline with the manifold right below the turbo, goes down and around, and up to the other manifold, almost like a factory Y pipe

Another:

This manifold goes on the pass. side, the downpipe is the crossover, and the main exhaust comes off the turbo at upper left.

http://www.forabodiesonly.com/mopar/showthread.php?p=1969435176

 

[Jbuhr]

I see and understand that one. I should be more specific about the manifolds I'm using. They are magnum style.

 

[67Dart273]

Also, don't forget headers. I'm not familiar with the present generation of Chevy stuff, but the old traditional SB Chevs, a header for one of those is VERY close to the same port spacing of a SB Mopar. I had a 340 in a FJ --40 Landcruiser, and used "Jeep swap" SB Chev headers. just welded the Chev flange to a blank Mopar flange and did some grinding. The middle two bolts even line up!!!!

This is a "converted" Chev to Mopar fit header. The top, middle flange is the original Chev flange

 

[71swing]

Summit sells headers for sm mopars that look just like the chevys above. I think they are hearman headers or somthing.

Yes your idea for the crossover is fine, a few companies design their mustang turbo kits this way. True most cross over the front. Thats just easier sometimes for the design. My turbo for mustang crosses in the front.

Ive seen plenty that have used a regular driver side header that does down and around the bellhousing and back up the otherside into the rear of the passenger header where it merges with the side exhaust and continues forward to the tubo mounted on the front of the passenger header.

What are your thoughts on down pipe exits. Thats the only downside to your rear crossover method is it takes up the room on both sides of the engine the headers normally ocupy. Thats why most do the front cross over, It leave that space open to run the downpipe back and down the firewall the same path as typical exhaust where it can normally be connected to your remaining exhaust with very little modifications.

Maybe you dont care for that and are just planning on dumping the exhaust up front somewhere?

 

[Jbuhr]

Here's a crude drawing of what I'd like to do. 71swing - I have to check the room for a downpipe. I think with the Magnum manifolds and the turbo facing forwards, there should be room for a 4 inch downpipe. I've left the intercooler out of the drawing, but I will be running one.

 

[jos51700]

If you don't have power steering, I'm pretty sure you can run the Magnum Jeep passenger manifold backwards on the driver's side and crossover under the front.

 

[71swing]

Well the oil filter is on that side as well so your most likely going to want to move that. 4" pipe is a good sized pipe and to be honest is just overkill. Its not needed. You can make the power with 3" and have a little more room for fitting pipe. Not familar with the magnum headers even thow I owned a dakota for some time. Is your cross over going connect to the headers normal ball and socket? Then you'll weld the turbo flange on the top? It may make changing plug a little difficult also if the turbo is right next to the valvecover. Youll just have to play with placement.

 

[71swing]

I also think you would make better on fitment if you moved the turbo placement to the front of the engine. The front passenger corner of the bay. there is plenty of room there to fit just about anything.

 

[67Dart273]

The thing is, if you can fabricate a steel log manifold AKA "header" that has outlets where you want it..................

but there's a pretty good reason why "everybody" is mounting them the way they do, and that is, that's about the easiest way.

 

[Jbuhr]

71swing - you answered another question of mine. I was thinking of putting the turbo at the front of the manifold too. Oil return line would be closer to the fuel block off plate and there's more room there.

Anyone try moving the power steering pump up towards the cylinder head? This would allow me to run the manifolds forward with the drivers side going under the ps pump, then to the right side.

I'm just brainstorming.

 

[trapster]

STS puts the turbo behind the rear wheels

http://ststurbo.com/single-universal-system-up-to-600hp

Just a thought

 

[MoparDaddy]

Certainly different. Seems effective in towing or heavy duty truck applications

 

[Jbuhr]

Well, after being at Car Craft this weekend, I've decided to build the Duster with a rear crossover, with the left side directly feeding the right side manifold. I decided this after refamiliarizing myself with the 3.8 turbo GM motors. They produce a lot of prove power with the same set up. I'll be sure to take photos and document the build and results.